The ureterovesical junction was studied by dissection and serial sections in 50 post mortem specimens. Three points are considered in this paper: the structure of the terminal ureter, the anatomical arrangement of the ureteral hiatus and the ureteral sheath. Study of the structure of the intramural segment of the ureter demonstrated on one hand, the perfect continuity of the terminal ureter with the trigone and on the other hand, the abundance of the fibroelastic connective fibers which like the muscle fibers run longitudinally. The compliance of the intravesical ureter is dependent on the balance between these two components. The modification of this balance can lead to the creation of a functional obstacle. The anatomical arrangement of the ureteral hiatus is described. The inner muscle layer of the detrusor extends almost to the ureteral orifice, the truly submucosal part of the ureter thus being very small. The constitution of the ureteral orifice and its relations to the ureter account for the different positions of juxtaureteral diverticula and transhiatal herniae of the bladder mucosa. The many descriptions of the ureteral sheath appearing in the literature are reviewed in light of the findings from the present study. The juxtavesical segment of the ureter is surrounded by a fibroconjunctive sheath which fixes the ureter to the bladder wall. The transparietal segment of the ureter is ensheathed in its adventitia, whereas a fibromuscular sheath cannot be truly individualized over this ureteral segment.